I saw this on a site and it was claimed the wheels could be raised for off rails driving. I think it would be a very fun thing to build, if not very practical (unless you took advantage of the on road speeds for a nice escape)

IMHO. I see what appears to bumpers on the tank hull. This may have been used to push the vehicle. Also the cables on the rear deck and completely unloaded suspension are addition indicators that it probably was just a dolly under the tank and not self driven while on the rails.

It also doesn't look like a permanent part of the tank, there is nowhere for the wheels to go when the suspension is loaded. I bet it's either a material saving prototype of specific railcar or just something made up in unit. They had specific cars for Tigers, maybe they tried something similiar for IIIs and IVs. It looks like there's a chassis since theres a dark block running the length between the wheels.

It was called a Panzer III Schienen-Kattefahrzeug SK1. There is a pretty good article at the bottom of the page of this link, including plans and a front view. http://axistanksworldwarii.devhub.co...pecial/page-3/ If you do a Google search for Panzer III SK1, you'll see a 1/35 model of it that someone built (no pictures of the underside, unfortunately). -Mike